When a user dials 911 (in the United States) on his/her user equipment (UE), the call is routed to an appropriate (e.g., nearest) public safety answering point (PSAP). Although today's telecom networks are fairly reliable, the UE, in some instances, may experience delays in establishing an emergency call with a PSAP. This can be due to various issues that arise from time-to-time inhibiting establishment of a communication session with the PSAP. For example, a network outage may occur during a particular emergency call attempt. In another example, such as during a natural disaster, incoming calls to the PSAP may be at such a high volume that calls may not get through to the PSAP, leading to prolonged ringing and delayed answering. The average user can only tolerate a certain amount of call silence time (e.g., 15 seconds to 25 seconds of silence) before the user panics or gets frustrated, hangs up the phone, and dials 911 again. Some users even exhibit this kind of behavior despite having heard a pre-recorded message encouraging the user to stay on the line and wait for the call to be answered.
However, rather than waiting an indefinite period of time for a network issue to resolve itself, the UE is typically configured to utilize call setup timers that timeout if something that is expected to occur during call setup does not occur within a set period of time. Accordingly, after a call setup timer is started, the UE can wait a set period of time until the timer expires, and thereafter take some remedial action. However, existing emergency call setup timers are problematic due to their configurations. For example, existing emergency call setup timer configurations can cause a spike in the amount of network traffic to/from the PSAP, thereby stressing the PSAP and making it difficult for the PSAP to recover, which may, in turn lead to dropped emergency calls. In view of the foregoing, emergency calls may go unanswered and emergency response services may be compromised. In recognizing that the aforementioned problems are, at least partly, caused by poorly-designed emergency call setup timers, there is a need for further improvements to UE call setup procedures utilizing timers for setting up emergency calls.